A dynamical inconsistency of Horava gravity

The dynamical consistency of the non-projectable version of Horava gravity is investigated by focusing on the asymptotically flat case. It is argued that for generic solutions of the constraint equations the lapse must vanish asymptotically. We then consider particular values of the coupling constants for which the equations are tractable and in that case we prove that the lapse must vanish everywhere -- and not only at infinity. Put differently, the Hamiltonian constraints are generically all second-class. We then argue that the same feature holds for generic values of the couplings, thus revealing a physical inconsistency of the theory. In order to cure this pathology, one might want to introduce further constraints but the resulting theory would then lose much of the appeal of the original proposal by Horava. We also show that there is no contradiction with the time reparametrization invariance of the action, as this invariance is shown to be a so-called "trivial gauge symmetry" in Horava gravity, hence with no associated first-class constraints.Comment: 28 pages, 2 references adde

Observations of OJ 287 from the Geodetic VLBI Archive of the Washington Correlator

We present 27 geodetic VLBI maps of OJ 287 obtained from the archive of the Washington correlator. The observations presented here were made between 1990 October and 1996 December. During this period a sequence of six superluminal components has been identified. We measured the proper motion of these components to be approximately 0.5 mas/yr, which is about twice as high as that seen in previous VLBI observations. These results imply a higher component ejection rate than previously observed, in good agreement with the observed occurrences of radio outbursts. We have examined a possible connection between VLBI components and optical flares in the framework of a binary black hole system.Comment: 9 pages, 5 included figures, emulateapj.sty, accepted to The Astrophysical Journa

Lepidópteros ocorrentes na safra e entressafra da soja no sudoeste do Mato Grosso.

Esta pesquisa verificou a ocorrência de lepidópteros desfolhadores durante a safra e entressafra da soja na região sudoeste do estado de Mato Grosso. O estudo foi conduzido na fazenda Aparecida da Serra (14°18'59"S, 57°45'16"W) (14°20'23"S, 57°42'39"W), localizada entre os municípios de Tangará da Serra e Nova Marilândia. No cultivo da soja (TMG 132RR), as coletas foram na safra 2012/13, em um talhão de 50 ha. Foram avaliados quatro transectos contendo 10 estacas cada, distantes 50 metros entre si, totalizando 40 pontos de coleta. Durante a entressafra, as avaliações ocorreram em um talhão de 145 ha contendo milheto (ADR 7010) e próximo ao cultivo de soja anterior. Nesse, foram estabelecidos 12 pontos de coleta, distribuídos em um transecto, cuja distância foi de 67 metros entre cada ponto, e de 134 m a cada quatro pontos. Na soja, 10 coletas foram feitas semanalmente (dezembro a fevereiro) com pano-de-batida, e no milheto, oito coletas quinzenalmente (maio a julho) por metro linear, além de coleta manual, por procura ativa, em ambos. O manejo utilizado pelo produtor na soja foi com defensivos químicos e, no milheto, não houve aplicação de produtos. Os lepidópteros coletados na soja foram Chrysodeixis includens Walker), Spodoptera sp., Heliothis virescens (Fabricius) e Anticarsia gemmatalis Hübner. No milheto ocorreram os noctuídeos Mocis latipes (Guenée), Spodoptera frugiperda (Smith), Helicoverpa sp., Helicoverpa armigera (Hübner), Mythimna sequax Franclemont, Helicoverpa zea (Boddie), Leucania latiuscula Herrich-Schäffer, o hesperíideo Urbanus proteus (Linnaeus), e um espécime de Geometridae. Conclui-se que o número de lepidópteros foi maior no milheto do que na soja, e, que exemplares da sub-família Heliothiinae e do gênero Spodoptera estiveram presentes durante os dois cultivos avaliados. Estes resultados contribuem para o conhecimento do complexo de insetos ocorrentes na safra e entressafra da soja e, potencialmente, para o manejo integrado de pragas

Novel efficient genome-wide SNP panels for the conservation of the highly endangered Iberian lynx

Background: The Iberian lynx (Lynx pardinus) has been acknowledged as the most endangered felid species in the world. An intense contraction and fragmentation during the twentieth century left less than 100 individuals split in two isolated and genetically eroded populations by 2002. Genetic monitoring and management so far have been based on 36 STRs, but their limited variability and the more complex situation of current populations demand more efficient molecular markers. The recent characterization of the Iberian lynx genome identified more than 1.6 million SNPs, of which 1536 were selected and genotyped in an extended Iberian lynx sample. Methods: We validated 1492 SNPs and analysed their heterozygosity, Hardy-Weinberg equilibrium, and linkage disequilibrium. We then selected a panel of 343 minimally linked autosomal SNPs from which we extracted subsets optimized for four different typical tasks in conservation applications: individual identification, parentage assignment, relatedness estimation, and admixture classification, and compared their power to currently used STR panels. Results: We ascribed 21 SNPs to chromosome X based on their segregation patterns, and identified one additional marker that showed significant differentiation between sexes. For all applications considered, panels of autosomal SNPs showed higher power than the currently used STR set with only a very modest increase in the number of markers. Conclusions: These novel panels of highly informative genome-wide SNPs provide more powerful, efficient, and flexible tools for the genetic management and non-invasive monitoring of Iberian lynx populations. This example highlights an important outcome of whole-genome studies in genetically threatened species

Diffusion-Reorganized Aggregates: Attractors in Diffusion Processes?

A process based on particle evaporation, diffusion and redeposition is applied iteratively to a two-dimensional object of arbitrary shape. The evolution spontaneously transforms the object morphology, converging to branched structures. Independently of initial geometry, the structures found after long time present fractal geometry with a fractal dimension around 1.75. The final morphology, which constantly evolves in time, can be considered as the dynamic attractor of this evaporation-diffusion-redeposition operator. The ensemble of these fractal shapes can be considered to be the {\em dynamical equilibrium} geometry of a diffusion controlled self-transformation process.Comment: 4 pages, 5 figure

New Pigeon Pea (\u3cem\u3eCajanus Cajan\u3c/em\u3e) Hybrids With Desirable Forage Traits

Pigeon pea is a tropical forage legume usually sown in mixed pastures with tropical forage grasses. Most of the available cultivars shows erect and tall plants with poor tillering potential, breakable thick stems, low leaf/stem ratios (fresh/dry matter) and low persistence under animal grazing. It shows a high dry matter production, due to low leaf/stem ratios (Barnes & Addo, 1997). Pigeon pea shows good crude protein levels/dry matter (ranging from 14-23%) and regular in vitro digestibility indexes (52-58%) (Karachi & Matata, 1996); animal consumption is affected by high tannin levels of young leaves. Being a self-pollinated species, the variability for forage traits occurs among cultivars available at germplasm banks. No significant variation is observed for any forage character within a given population. Effective selection and releasing of new genetic materials bearing desirable morpho-agronomic and forage traits is mostly dependent on increases of genetic variation, which may be accomplished through artificial crossings between selected parentals. This research work was aimed at the synthesis of new pigeon pea hybrids, hopefully bearing new desirable forage characters

Manejo de solo e água e opções de cultivo em barragem subterrânea.

Este trabalho objetivou a construção do conhecimento sobre manejo do solo e uso da água de barragem subterrânea, bem como avaliar os parâmetros construtivos da tecnologia

Yield and Quality Parameters of an Interspecific Hybrid \u3cem\u3ePennisetum Purpureum\u3c/em\u3e Schum. (Elephant-Grass) \u3cem\u3eX Pennisetum Glaucum\u3c/em\u3e (L.) R. Br. Stuntz (Pearl Millet)

Elephant-grass is a tropical forage grass used either as a supplement fodder or for direct grazing. It usually shows regular nutritive value (6-13% crude protein, CP, and 55-60% forage digestibility) (Alcantara et al., 1981). Most of the available cultivars produce no viable seeds. On the other hand, pearl millet has high seed yielding potential along with high quality forage (\u3e15% CP and 70% forage digestibility). However, it shows poor forage production, low field persistence under grazing and low regrowth potential after cutting or grazing. During the 90\u27s, an interspecific hybrid between the two species was developed, trying to combine the elephant-grass adaaptability and forage yielding potential with the pearl millet forage quality and seed yielding potential (Schank et al., 1993; Schank, 1996). The new genetic material was able to produce viable seeds in variable amounts (Diz et al., 1995). The main aim of this research was to produce selected populations with high phenotypic uniformities, showing high average forage production and quality

Ac transport studies in polymers by a resistor network and transfer matrix approaches: application to polyaniline

A statistical model of resistor network is proposed to describe a polymer structure and to simulate the real and imaginary components of its ac resistivity. It takes into account the polydispersiveness of the material as well as intrachain and interchain charge transport processes. By the application of a transfer matrix technique, it reproduces ac resistivity measurements carried out with polyaniline films in different doping degrees and at different temperatures. Our results indicate that interchain processes govern the resistivity behavior in the low frequency region while, for higher frequencies, intrachain mechanisms are dominant.Comment: LaTeX file, 15 pages, 5 ps figures, to appear in Phys. Rev.

Avaliação de parâmetros químicos da água de chuva armazenada em poços e área de plantio de barragens subterrâneas.

É recomendada, quando possível, na construção das unidades produtivas a locação de poços dentro da área de plantio objetivando renovação da água